Datatype library primitives shared between clojurescript and clojure.  The datatype
system is an extensible system to provide understanding of and access to an undefined
set of datatypes and containers that hold contiguous sections of those datatypes.

Generalized efficient manipulations of sequences of primitive datatype.  Includes
specializations for java arrays and nio buffers.  There are specializations to allow
implementations to provide efficient full typed copy functions when the types can be
ascertained.  Usually this involves a double-dispatch on both the src and dest
arguments:

https://en.wikipedia.org/wiki/Double_dispatch.

Generic operations include:
1. datatype of this sequence.
2. Writing to, reading from.
3. Construction.
4. Efficient mutable copy from one sequence to another.

Java specific mappings of the datatype system.